rotor cranks

"ari" <[email hidden]> wrote in message news:8c1ec.400$fS6.317@okepread01...

Quoted message said:

From reading their site (www.rotorcranks.com), it looks like one of the
crank arms is arranged at 1 o'clock while the other is in the
traditional 6 o'clock.

If I had a shimano octalink splined BB/cranks, could'nt I just install
one of the arms incorrectly in order to achieve the same effect? The
rotor cranks are >$500 and I have no idea why, what am I missing.

It looks like they switch twice each time each pedal rotation so that your
top foot is always slightly past 12:00 when your bottom foot is at 6:00.
I'm not sure it's as far ahead as 1:00, but let's say it is. If you fixed a
regular set of cranks to achieve the 1&6 position when one foot was up, they
would be at a 11&6 position when the other foot was up, causing a loss in
power.

--
Scott Ehardt
http://www.scehardt.com

ari may have said:

From reading their site (www.rotorcranks.com), it looks like one of the
crank arms is arranged at 1 o'clock while the other is in the
traditional 6 o'clock.

If I had a shimano octalink splined BB/cranks, could'nt I just install
one of the arms incorrectly in order to achieve the same effect? The
rotor cranks are >$500 and I have no idea why, what am I missing.

No, the idea behind the rotor cranks is that the pedals do not work
precisly in synch at all; as the BB shaft rotates, each crank's
position relative to it *changes*, increasing the mechanical advantage
of the leg where it supposedly can be beneficial to do so, and
speeding the return of the foot to the power production point in the
cycle. That's the theory. In practice, they're heavy, and they're
not proven to be sufficiently beneficial to make me have the least
interest in them. In particular, I have yet to see any definitive
information regarding how much friction loss there is within the
system itself; this could easily outweigh any supposed advantage.

--
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